1. Field of the Invention
This invention is directed to a vehicle wheel brake actuator assembly and more specifically to improved means for mounting a fluid pressure motor to a wedge brake actuator housing.
The invention comprises a novel arrangement of elements for quickly and conveniently securing the tubular support of a fluid pressure motor to the brake actuator housing with the tubular support rotated and axially positioned relative to the housing to provide maximum brake performance and access for service and replacement purposes.
The invention is particularly useful in wedge actuated brakes of the types disclosed in U.S. Pat. No. 3,037,584. Such brakes are usually actuated by an air motor which drives a wedge reciprocably between a pair of plungers which serve to displace associated brake shoes into frictional contact with a surrounding brake drum. In such brakes it is of course important that the wedge be axially located in a predetermined position relative to the plungers in order to maintain maximum brake performance when the air motor is activated. It is also important that the means for mounting the air motor to the actuator housing be such as to permit rotation of the air motor to accommodate connection of the air lines. The means for securing the air motor to the actuator housing must also be durable enough to maintain integrity of the brake system and readily accessible and easy to attach and remove in order to facilitate maintenance, inspection and replacement services performed on the vehicle.
2. Description of the Prior Art
A number of different devices have been employed to connect a tubular fluid motor support to a wedge brake actuator housing. U.S. Pat. No. Re. 27,257 which issued to F. T. Cox et al. on Dec. 28, 1971 discusses the prior use of a "simple threaded connection" and then discloses the use of a lock ring wedged between a threaded connection to secure the assembly after the tubular support has been axially located relative to the actuator housing. When properly installed the lock nut has proven satisfactory in service but the nut is located in such an environment and is of such a dimension that at times it is difficult to engage a wrench on the lock nut with adequate clearance to fully tighten or loosen the lock nut.
Another assembly is disclosed in U.S. Pat. No. 3,434,359 which issued on Mar. 25, 1969 to W. J. Williams et al. In that patent a ring is rigidly secured circumferentially around a tubular support of an air motor and a retainer is drawn into abutment with that ring by means of nuts tightened on studs threaded to the actuator housing to force the end of the tubular support against a shoulder in a bore of the actuator housing. Although that assembly permits complete rotation of the tubular support relative to the actuator housing, the location of the studs in the actuator housing is pre-established and the stud and nut assembly may not be readily accessible in every vehicle installation.